The present invention relates to the field of manufacturing parts having a directed crystallographic orientation, especially single-crystal parts, by directional solidification of an alloy of cubic crystallographic structure in a shell mold. More particularly, the solidification is carried out from a starter seed.
Directional solidification consists in feeding a mold with molten metal and in making the solidification front advance along a growth axis with a predetermined crystallographic orientation. In nickel superalloys for example, the <001> orientation predominates. However, there are also solidification modes which make it possible for the solidification to be also oriented relative to a plane perpendicular to the primary solidification axis. The crystallographic orientation measured along the principal axis of a cast part is called the primary orientation and the polar orientation in a plane perpendicular to the principal axis is called the transverse or secondary orientation.
The invention applies to single-crystal parts for which it is necessary to respect a <001> primary crystalline orientation.
The invention applies more particularly to single-crystal parts for which two crystalline orientations are to be respected, namely a <001> primary crystalline orientation and an <010> transverse orientation with respect to the solidification axis.